U. S. Department of the Interior

U. S. Geological Survey

Open-File Report 2005-1014

January 2005

Surveys (SANDS), which allows 

mapping in water that is 50 cm or 

deeper. The SANDS system is towed 

by a boat. In addition, NASA is using 

a LIDAR (LIght Detection And Ranging) system, known as Experimental 

Advanced Airborne Research Lidar 

(EAARL), which uses a laser sent 

from an aircraft to measure the seafloor 

in shallower water near the coastline. 

The EAARL system is used to record 

bathymetric data close to shore where 

it is too shallow for a boat.

Benthic habitat mapping

Various techniques can be used to 

map benthic habitats. Hydroacoustics 

can differentiate bottom types but are 

less sensitive to differences in biotic 

communities. Digital videos and still 

photography provide information 

Introduction

Tampa Bay, Florida, and its environs have experienced phenomenal 

urban growth and significant changes 

in land-use practices over the past 

50 years. This trend is expected to 

continue, with human activity intensifying and affecting a wider geographic region. Urbanization creates 

impervious surfaces, which increase 

stormwater runoff and contribute to 

greater amounts of chemicals flowing 

into coastal waters. Man-made structures including bridges, a gas pipeline, 

desalination plant, ports, navigation 

channels, and extensive sea walls 

have been built and will continue to 

be maintained and modified. This task 

of the Tampa Bay Study aims to provide a better understanding of these 

and other man-made impacts on the 

Tampa Bay region.

Approach

An integrated coastal model for 

Tampa Bay will be used to investigate 

water circulation and transport of sediments and contaminants and resulting 

impact on the Tampa Bay ecosystem. 

Before the models can be applied 

accurately, seafloor and watershed 

data must be collected for the bay. 

Historical maps that document 

changes in land use and wetlands, 

as well as water quality and biological data, provide an understanding of 

land-use change in the past and the 

impact it had on Tampa Bay. This historical information is used to develop 

models that predict land-use changes 

to 2025 and their possible impact on 

ecosystems.

Seamless maps

Hydrographic charts and topographic survey maps dating back to 

the mid-1800s are being used to create 

historical digital elevation models of 

the region so changes in the configuration of the coastline and seafloor can 

be tracked. Using elevation data compiled by the U. S. Geological Survey 

(USGS) and depth data collected by 

National Oceanographic and Atmospheric Administration (NOAA), 

scientists have created a seamless map 

for the 5180-km2 watershed of Tampa 

Bay based on 30-m data spacing. An 

improved map at 10-m data spacing 

has recently been completed. 

Topographic and bathymetric 

mapping

Scientists from the USGS and 

the National Aeronautics and Space 

Administration (NASA) are teaming 

up to map the seafloor and coastline 

of Tampa Bay. The USGS has developed an acoustic-based system named 

System for Accurate Nearshore Depth 

Predictive urban growth models will be utilized 

to predict population growth patterns in the 

Tampa Bay region. The models will also assess 

how land-use patterns will change over time, 

and their impact on the region’s ecosystems 

and local climate.

Tampa Bay Study area showing the seismic 

tracklines and bathymetry. Scientists are using 

seismic surveying and bathymetric mapping to 

study the subsurface geology and seafloor of 

Tampa Bay.

Gulf of Mexico Integrated Science - Tampa Bay Study

Watershed and Estuary Mapping
Mark Hansen, Task Leader, Email: mhansen@usgs.gov

U.S. Geological Survey, Geologic Discipline

600 4th Street South, St. Petersburg, FL 33701

Michael Crane, Task Leader, Email: mpcrane@usgs.gov

U.S. Geological Survey, National Mapping Discipline

Eros Data Center, 4794 252nd Street, Sioux Falls, SD 57198

Clif Hearn, Integrated Modeling, Email: cjhearn@usgs.gov

ETI Professionals, Inc., at U.S. Geological Survey

600 4th Street South, St. Petersburg, FL 33701

Kimberly Yates, Project Chief, Email: kyates@usgs.gov

U.S. Geological Survey, Geologic Discipline

600 4th Street South, St. Petersburg, FL 33701

Gregg Brooks, Eckerd College

Kurt Hess, National Oceanic and Atmospheric Administration

Al Hine, University of South Florida

Toni Janicki, Janicki Environmental

Stan Locker, University of Florida

Dennis Milbert, National Oceanic and Atmospheric Administration

Mark Luther, University of South Florida

Bruce Parker, National Oceanic and Atmospheric Administration

Robert Wilson, National Oceanic and Atmospheric Administration

Wayne Wright, National Aeronautic and Space Administration

For more information, please contact:

http://gulfsci.usgs.gov

Contributing Scientists:

on the biotic habitats but are lacking 

in detail. The USGS and NASA are 

developing a technique that would 

use LIDAR to identify habitats. 

Hydroacoustic, video, photographic, 

and LIDAR data will be integrated 

to map seafloor communities such as 

seagrass, oyster beds, algae, sand, and 

mud.

Seismic surveying

Contamination from groundwater 

sources is a major concern in Tampa 

Bay. Some scientists estimate that 20 

percent of the fresh water flowing into 

Tampa Bay comes from groundwater, 

although it is unknown where groundwater seepage occurs. Three different 

aquifer systems sit beneath Tampa 

Bay, and because of their proximity 

to the seafloor, two of them might be 

sources of groundwater entering the 

bay. Seismic surveying aims to identify the location and depth of shallow 

aquifers beneath Tampa Bay. 

To survey the floor of the bay, a 

seismic system is used that emits a 

sound at a regular interval and records 

it as it bounces back from the seafloor. 

The time the sound takes to return 

from the seafloor is used to calculate 

water depth and to record sediment 

layers beneath the seafloor. 

Predictive modeling

Baseline mapping data is used to 

predict where urbanization will occur 

in the future. The SLEUTH (Slope, 

Land use, Excluded lands, Urban 

land, Transportation, and Hill shading) model predicts changes in land 

use over time. The SLEUTH model 

is being run on a cluster of PC computers that provide processing power 

approaching supercomputer capability. The model will simulate urban 

growth from the 1950s through 2025. 

Major land-cover categories also will 

be modeled to study potential impacts 

to ecosystems in the region.

Scientists from the USGS, University of South Florida (USF), and 

Janicki Environmental are partnering to develop Tampa Bay Integrated 

Coastal Models or TB-ICMs. The TBICM has five components including 

circulation, water quality, sediment 

transport, advection and diffusion, 

and submerged aquatic vegetation. 

Scientists and resource managers will 

use this model to predict how natural 

and man-made changes to the physical structure or water chemistry of 

the bay may affect water quality and 

marine life.

Vulnerability to major hazards

Rapid growth in the Tampa Bay 

area is placing an ever-increasing proportion of the population and attendant 

development at risk from the variety 

of natural disasters that occur in this 

region. Using baseline mapping data 

in conjunction with data from federal, 

state, and local government agencies, 

as well as urban-growth predictions, 

a geographical analysis is being conducted of the current and anticipated 

vulnerability of the population and 

development to phenomena such as 

hurricanes, flooding, tornadoes, and 

wildfires. The study examines many 

aspects, such as changes in the location and configuration of the coastline, distribution and density of the 

population, and the commercial and 

industrial sectors. 

Links to other project 

research

Baseline maps provide the physical context, background, and baseline 

information for other project research, 

monitoring, and modeling activities. 

Elevation, habitat, and water-quality 

mapping provide critical information 

for development of circulation, hydrologic, sediment transport, water quality, 

and urbanization integrated modeling. 

Seismic mapping will be coupled with 

groundwater mapping and research to 

aid in the identification and quantification of groundwater sources, and to aid 

geologists in bay-wide reconstruction 

of the geologic history and development of Tampa Bay.

Scientists from the USGS and University of South 

Florida prepare the seismic sled for deployment 

in Tampa Bay. The sled collects seismic reflection data that can be interpreted to determine 

the subsurface geology of Tampa Bay.